Chapter 8

Question 1

Autotrophs

Answer 1

Autotrophs are living organisms that are able to make their own food without using organic molecules derived from any other living source.

Question 2

Photoautotrophs

Answer 2

Autotrophs that use the energy of light to produce organic molecules are called photoautotrophs.

Most plants, algae, and some protists, as well as some prokaryotes (bacteria) are photoautotrophs.

Question 3

Heterotrophs

Answer 3

Heterotrophs are organisms that cannot produce their own food using inorganic molecules, and must consume organic materials derived from other living sources for food.

Question 4

Producers

Answer 4

Autotrophs

Question 5

Consumers

Answer 5

Heterotrophs

Question 6

Photosynthesis

Answer 6

A process that converts solar energy to chemical energy.

Question 7

Chloroplasts

Answer 7

Chloroplasts are organelles consisting of photosynthetic pigments, enzymes, and other molecules grouped together in membranes.

Question 8

Photosynthesis occurs in ________ in plant cells.

Answer 8

chloroplasts

Question 9

Chlorophyll

Answer 9

An important light absorbing pigment in chloroplasts, responsible for the green color of plants. Chlorophyll plays a central role in converting solar energy to chemical energy.

Question 10

Mesophyll

Answer 10

Chloroplasts are concentrated in the cells of the mesophyll, the green tissue in the interior of the leaf.

Question 11

Stomata

Answer 11

Stomata are tiny pores in the leaf that allow carbon dioxide to enter and oxygen to exit.

Question 12

Stroma

Answer 12

The dense fluid within the chloroplast.

Question 13

Thylakoids

Answer 13

A system of interconnected membranous sacs called thylakoids segregates the stroma from a another compartment in the chloroplast called the thylakoid space.

Question 14

Grana

Answer 14

Thylakoids are concentrated in stacks called grana.

Question 15

Photosynthesis is a ______ process.

Answer 15

redox (oxidation-reduction)

Question 16

The two stages of photosynthesis

Answer 16

1. Light reaction

2. Dark reaction (Calvin cycle)

Question 17

Light reactions

Answer 17

In the light reactions of photosynthesis, light energy is converted in the thylakoid membranes to chemical energy and O2.
Water is split to provide the O2 as well as electrons.
H+ ions reduce NADP+ to NADPH.

The light reactions generate ATP.

Question 18

NADPH

Answer 18

An electron carrier similar to NADH.

Question 19

Dark reactions/light-independent/Calvin cycle

Answer 19

Occurs in the stroma of the chloroplast.
It is a cyclic series of reactions that builds sugar molecules from CO2 and the products of the light reactions.
During the Calvin cycle, CO2 is incorporated into organic compounds, a process called carbon fixation.

NADPH produced by the light reactions provides the electrons for reducing carbon in the Calvin cycle.
ATP from the light reactions provides chemical energy for the Calvin cycle.

Question 20

Sunlight contains energy called ____________ energy or _________.

Answer 20

electromagnetic, radiation

Question 21

_____________ energy travels in waves

Answer 21

Electromagnetic

Question 22

Wavelength

Answer 22

The distance between the crests of two adjacent waves.

Question 23

Photon

Answer 23

A photon is a fixed quantity of light energy.

Question 24

The ________ the wavelength, the greater the energy.

Answer 24

shorter

Question 25

Pigments

Answer 25

Molecules that absorb light.

Question 26

Chlorophyll a

Answer 26

Absorbs blue, violet, and red light and reflects green.

Question 27

Chlorophyll b

Answer 27

Absorbs blue and orange and reflects yellow-green.

Question 28

Carotenoids

Answer 28

Absorb mainly blue-green light and reflect yellow and orange.

Question 29

Photosystems

Answer 29

The energy released during photosynthesis could be lost as heat or light, but rather it is conserved as it passes from one molecule to another molecule. All of the components to accomplish this are organized in thylakoid membranes in clusters called photosystems. Photosystems are light-harvesting complexes surrounding a reaction center complex.

Question 30

Photosystem I

Answer 30

Photosystem I, which functions after photosystem II, is called P700 because it absorbs light with a wavelength of 700 nm.

Question 31

Photosystem II

Answer 31

Photosystem II, which functions before photosystem I, is called P680 because it absorbs light with a wavelength of 680 nm.

Question 32

Two ___________ connected by an electron transport chain generate ATP and NADPH.

Answer 32

photosystems